[Dave Martin]"I have a MacPro and a MacBook Pro. I just got my IO HD and the manual says to uninstall the IO before installing IO HD. I guess that pretty much means I can't switch the two boxes back and forth at will? "

there is no need to..

The IoHD can handle all of the same formats in SD that the original unit did so there is no need to have both on your computer at the same time.

I'll see if I can explain a little better. I'd like to take the IO HD and use it on the laptop or Mac Pro as needed. When I take the IOHD on the road for instance...I'd like to hook up the IO to the Mac Pro to monitor SD etc...does that make more sense?